In many of electronic apparatus, Light Emitting Diodes (LEDs) and various shapes of symbols respectively associated with the LEDs are often arranged side by side on the outer surface of a cover of the housing accommodating the electronic apparatus. This arrangement is provided to inform a user that the electronic apparatus is in the state represented by a symbol, by way of turning on or blinking the LED associated with the symbol. Similarly, when push buttons are employed, symbols are provided on or next to the respective push buttons so that a user can understand what kind of operation would start upon a press of a button by merely looking at the symbol associated with the button.
However, arranging multiple symbols and LEDs on the outer surface of a cover of the housing accommodating an electronic apparatus has such a problem that the electronic apparatus appears untidy, impairing the design of the apparatus.
Japanese Unexamined Utility Model Application Publication No. 6-33334 discloses a technique for solving the above-described problem. This publication discloses an illumination switch having a cover. On the outer surface of the cover, a flexible film is disposed. A mark is formed on the inner surface of the flexible film, and a smoke material layer is disposed on the mark. In this structure, the inside of the switch is invisible. The illumination switch contains a light source disposed under the mark. When light is emitted from the light source, the mark appears on the surface of the smoke material layer as it is illuminated.
According to this illumination switch, since the mark appears on the outside only when the light is emitted from the light source, flexibility in design can be achieved, thereby improving the design of the entire device.
In the illumination switch according to the above-mentioned Publication No. 6-33334, a pushbutton switch is disposed inside the cover. Therefore, when the part where the mark appears on the smoke material layer of the flexible film is pressed, the operation according to the mark begins.
In the case of the Publication No. 6-22224 however, since it is difficult to arrange the push button switch at a position corresponding to the light source disposed on the inner side of the flexible film, the push button switch is arranged adjacent to the light source. Accordingly, the Publication No. 6-33334 requires a member that allows a pressing force by a finger to be transmitted to the pushbutton switch disposed next to the part of the flexible film where the mark appears (i.e. adjacent to the light source), when that part is pressed by the finger. Further, the flexible film per se requires a complicated structure because it is formed by disposing the smoke material layer and forming the mark on a transparent sheet-like base. For this reason, the illumination switch requires a large capacity inside the cover, increasing the cost. Furthermore, the illumination switch is very likely to have a problem in durability because the flexible sheet is deformed every time a pressing force by a finger is transmitted to the push button switch.